U.S. patent application number 12/449219 was filed with the patent office on 2010-01-07 for vehicle, controller for the vehicle, and method of controlling the vehicle.
This patent application is currently assigned to TOYOTA JIDOSHA KABUSHIKI KAISHA. Invention is credited to Takaya Soma.
Application Number | 20100004806 12/449219 |
Document ID | / |
Family ID | 39759529 |
Filed Date | 2010-01-07 |
United States Patent
Application |
20100004806 |
Kind Code |
A1 |
Soma; Takaya |
January 7, 2010 |
Vehicle, Controller for the Vehicle, and Method of Controlling the
Vehicle
Abstract
An ECU includes: a feedforward torque calculation unit for
calculating a feedforward term of torque which reduces vibrations
of a vehicle, by inputting a sum of a first requested driving
force, which is identified as torque requested by a driver, and
brake force into a vehicle model; a feedback torque calculation
unit for calculating a feedback term of the torque which reduces
vibrations of the vehicle, by inputting second requested driving
force calculated from a revolution speed of wheels into the vehicle
model; a second driving force calculation unit for calculating
driving force to be achieved by an MG, by subtracting driving force
to be achieved by an engine and an MG from a sum of the first
requested driving force, the brake force, and the feedforward term
and the feedback term of the torque which reduces vibrations of the
vehicle; and an MG control unit for controlling MG to achieve the
calculated driving force.
Inventors: |
Soma; Takaya; (Toyota-shi,
JP) |
Correspondence
Address: |
OLIFF & BERRIDGE, PLC
P.O. BOX 320850
ALEXANDRIA
VA
22320-4850
US
|
Assignee: |
TOYOTA JIDOSHA KABUSHIKI
KAISHA
Toyota-shi, Aichi-ken
JP
|
Family ID: |
39759529 |
Appl. No.: |
12/449219 |
Filed: |
March 5, 2008 |
PCT Filed: |
March 5, 2008 |
PCT NO: |
PCT/JP2008/054438 |
371 Date: |
July 29, 2009 |
Current U.S.
Class: |
701/22 ;
903/915 |
Current CPC
Class: |
B60L 50/61 20190201;
Y10T 477/23 20150115; Y02T 10/72 20130101; B60W 10/26 20130101;
B60L 15/20 20130101; B60W 10/06 20130101; Y02T 10/7072 20130101;
Y02T 10/64 20130101; B60K 1/02 20130101; B60L 2240/12 20130101;
B60K 6/445 20130101; B60L 2240/423 20130101; B60W 10/08 20130101;
B60W 2555/20 20200201; Y02T 10/70 20130101; B60W 20/00 20130101;
B60L 2250/26 20130101; B60L 2240/443 20130101; Y02T 10/62 20130101;
B60L 50/16 20190201; B60L 2270/145 20130101; B60L 2240/461
20130101 |
Class at
Publication: |
701/22 ;
903/915 |
International
Class: |
B60W 20/00 20060101
B60W020/00; B60W 10/06 20060101 B60W010/06; B60W 10/08 20060101
B60W010/08 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 7, 2007 |
JP |
2007/057534 |
Claims
1. A vehicle, comprising: a differential mechanism having a first
rotary element coupled to a first rotating electrical machine, a
second rotary element coupled to a second rotating electrical
machine, and a third rotary element coupled to an engine; a wheel
to which torque is transmitted from said second rotary element, and
an operation unit, said operation unit calculating torque which
reduces vibrations of said vehicle, and controlling any one of said
second rotating electrical machine and said engine such that the
controlled one of said second rotating electrical machine and said
engine outputs the torque which reduces vibrations of said
vehicle.
2. The vehicle according to claim 1, wherein said operation unit
calculates torque to be outputted from said second rotating
electrical machine, by factoring in the torque which reduces
vibrations of said vehicle, and controls said second rotating
electrical machine such that said second rotating electrical
machine outputs the torque calculated by factoring in the torque
which reduces vibrations of said vehicle to thereby output the
torque which reduces vibrations of the said vehicle.
3. The vehicle according to claim 2, wherein said vehicle is
mounted with a power storage mechanism for storing electric power
to be supplied to said second rotating electrical machine, and said
operation unit calculates a limit value of a charging electric
power value of said power storage mechanisms, calculates a limit
value of a discharging electric power value of said power storage
mechanism, changes a gain in accordance with at least any one of
the limit value of said charging electric power value and the limit
value of said discharging electric power value, calculates torque
requested by a driver, and calculates the torque which reduces
vibrations of said vehicle, by using a product of the torque
requested by the driver and said gain.
4. The vehicle according to claim 2, wherein said vehicle further
comprises an atmospheric pressure sensor for detecting an
atmospheric pressure, and said operation unit changes a gain in
accordance with the atmospheric pressure, calculates torque
requested by a driver, and calculates the torque which reduces
vibrations of said vehicle, by using a product of the torque
requested by the driver and said gain.
5. The vehicle according to claim 1, wherein said operation unit
calculates torque to be outputted from said engine by factoring in
the torque which reduces vibrations of said vehicle, and controls
said engine such that said engine outputs the torque calculated by
factoring in the torque which reduces vibrations of said vehicle to
thereby output the torque which reduces vibrations of said
vehicle.
6. A method of controlling a vehicle including a differential
mechanism having a first rotary element coupled to a first rotating
electrical machine, a second rotary element coupled to a second
rotating electrical machine, and a third rotary element coupled to
an engine, and a wheel to which torque is transmitted from said
second rotary element, the method comprising the steps of:
calculating torque which reduces vibrations of said vehicle; and
controlling any one of said second rotating electrical machine and
said engine such that the controlled one of said second rotating
electrical machine and said engine outputs the torque which reduces
vibrations of said vehicle.
7. The method of controlling the vehicle according to claim 6,
wherein said controlling method further comprises the step of
calculating torque to be outputted from said second rotating
electrical machine, by factoring in the torque which reduces
vibrations of said vehicle, and the step of controlling any one of
said second rotating electrical machine and said engine includes
the step of controlling said second rotating electrical machine
such that said second rotating electrical machine outputs the
torque calculated by factoring in the torque which reduces
vibrations of said vehicle to thereby output the torque which
reduces vibrations of the said vehicle.
8. The method of controlling the vehicle according to claim 7,
wherein said vehicle is mounted with a power storage mechanism for
storing electric power to be supplied to said second rotating
electrical machine, said controlling method further comprises the
steps of calculating a limit value of a charging electric power
value of said power storage mechanism, calculating a limit value of
a discharging electric power value of said power storage mechanism,
changing a gain in accordance with at least any one of the limit
value of said charging electric power value and the limit value of
said discharging electric power value, and calculating torque
requested by a driver, and the step of calculating the torque which
reduces vibrations of said vehicle includes the step of calculating
the torque which reduces vibrations of said vehicle, by using a
product of the torque requested by the driver and said gain.
9. The method of controlling the vehicle according to claim 7,
wherein said controlling method further comprises the steps of
detecting an atmospheric pressure, changing a gain in accordance
with the atmospheric pressure, and calculating torque requested by
a driver, and the step of calculating the torque which reduces
vibrations of said vehicle includes the step of calculating the
torque which reduces vibrations of said vehicle, by using a product
of the torque requested by the driver and said gain.
10. The method of controlling the vehicle according to claim 6,
wherein said controlling method further comprises the step of
calculating torque to be outputted from said engine by factoring in
the torque which reduces vibrations of said vehicle, and the step
of controlling any one of said second rotating electrical machine
and said engine includes the step of controlling said engine such
that said engine outputs the torque calculated by factoring in the
torque which reduces vibrations of said vehicle to thereby output
the torque which reduces vibrations of said vehicle.
11. A controller for a vehicle including a differential mechanism
having a first rotary element coupled to a first rotating
electrical machine, a second rotary element coupled to a second
rotating electrical machine, and a third rotary element coupled to
an engine, and a wheel to which torque is transmitted from said
second rotary element, said controller comprising: calculation
means for calculating torque which reduces vibrations of said
vehicle; and control means for controlling any one of said second
rotating electrical machine and said engine such that the
controlled one of said second rotating electrical machine and said
engine outputs the torque which reduces vibrations of said
vehicle.
12. The controller for the vehicle according to claim 11, wherein
said controller further comprises means for calculating torque to
be outputted from said second rotating electrical machine, by
factoring in the torque which reduces vibrations of said vehicle,
and said control means includes means for controlling said second
rotating electrical machine such that said second rotating
electrical machine outputs the torque calculated by factoring in
the torque which reduces vibrations of said vehicle to thereby
output the torque which reduces vibrations of said vehicle.
13. The controller for the vehicle according to claim 12, wherein
said vehicle is mounted with a power storage mechanism for storing
electric power to be supplied to said second rotating electrical
machine, said controller further comprises means for calculating a
limit value of a charging electric power value of said power
storage mechanism, means for calculating a limit value of a
discharging electric power value of said power storage mechanism,
means for changing a gain in accordance with at least any one of
the limit value of said charging electric power value and the limit
value of said discharging electric power value, and means for
calculating torque requested by a driver, and said calculation
means includes means for calculating the torque which reduces
vibrations of said vehicle, by using a product of the torque
requested by the driver and said gain.
14. The controller for the vehicle according to claim 12, wherein
said controller further comprises means for detecting an
atmospheric pressure, means for changing a gain in accordance with
the atmospheric pressure, and means for calculating torque
requested by a driver, and said calculation means includes means
for calculating the torque which reduces vibrations of said
vehicle, by using a product of the torque requested by the driver
and said gain.
15. The controller for the vehicle according to claim 11, wherein
said controller further comprises means for calculating torque to
be outputted from said engine by factoring in the torque which
reduces vibrations of said vehicle, and said control means includes
means for controlling said engine such that said engine outputs the
torque calculated by factoring in the torque which reduces
vibrations of said vehicle to thereby output the torque which
reduces vibrations of said vehicle.
Description
TECHNICAL FIELD
[0001] The present invention relates to a vehicle, a controller for
the vehicle, and a method of controlling the vehicle, and
particularly relates to a technique of reducing vibrations of the
vehicle.
BACKGROUND ART
[0002] In recent years, as part of measures to address
environmental problems, an attention has been given to a hybrid
vehicle, an electric vehicle, a fuel-cell vehicle, and the like
that can run by driving force obtained from a rotating electrical
machine (electric motor). Such a vehicle also vibrates during
running under the influence of driving force of the vehicle itself,
a state of a road surface, and others. Therefore, techniques of
suppressing vibrations of the vehicle have been proposed.
[0003] Japanese Patent Laying-Open No. 2005-020831 discloses a
driving force controller for reducing back and forth vibrations of
an electric-powered vehicle, wheels of which are driven by a motor.
This driving force controller includes: a standard driving force
calculation unit for calculating standard driving force
corresponding to an operation state of the vehicle; a road surface
uneven portion detection unit for detecting a road surface uneven
portion over which wheels pass during running; an additional
driving force calculation unit for calculating additional driving
force for the wheels, which additional driving force reduces wheel
speed variations caused by the passage over the uneven portion; a
composite driving force calculation unit for calculating composite
driving force by adding up the additional driving force and the
standard driving force; and a motor driving force control unit for
controlling driving force of the motor such that the composite
driving force is provided to the wheels.
[0004] According to the driving force controller described in this
publication, when the wheels pass over a road surface uneven
portion, the wheels are provided with the composite driving force,
which is a sum of the additional driving force which reduces wheel
speed variations caused by the passage over the uneven portion, and
the standard driving force corresponding to the vehicle operation
state. It is thereby possible to reduce back and forth vibrations
of the vehicle body, caused by the variations in wheel speed during
the passage over the uneven portion.
[0005] Some hybrid vehicles have an engine and two rotating
electrical machines, and use the engine and one of the rotating
electrical machines as a driving source, and use the other of the
rotating electrical machines as an electric power generator. In
such hybrid vehicles as well, it is desired to reduce the
vibrations thereof. However, the driving force controller described
in Japanese Patent Laying-Open No. 2005-020831 has no description
about such hybrid vehicles.
DISCLOSURE OF THE INVENTION
[0006] An object of the present invention is to provide a vehicle
having an engine and two rotating electrical machines and capable
of reducing vibrations, a controller for the vehicle, and a method
of controlling the vehicle.
[0007] A vehicle according to a certain aspect of the present
invention includes: a differential mechanism having a first rotary
element coupled to a first rotating electrical machine, a second
rotary element coupled to a second rotating electrical machine, and
a third rotary element coupled to an engine; a wheel to which
torque is transmitted from the second rotary element; and an
operation unit. The operation unit calculates torque which reduces
vibrations of the vehicle, and controls any one of the second
rotating electrical machine and the engine such that the controlled
one of the second rotating electrical machine and the engine
outputs the torque which reduces vibrations of the vehicle.
[0008] According to this configuration, the differential mechanism
has the first rotary element coupled to the first rotating
electrical machine, the second rotary element coupled to the second
rotating electrical machine, and the third rotary element coupled
to the engine. Torque is transmitted to the wheels of the vehicle
from the second rotary element. Any one of the second rotating
electrical machine and the engine is controlled to output the
torque which reduces vibrations of the vehicle. It is thereby
possible to provide the torque which reduces vibrations of the
vehicle to the wheels. Accordingly, it is possible to reduce
vibrations of the vehicle having an engine and two rotating
electrical machines.
[0009] Preferably, the operation unit calculates torque to be
outputted from the second rotating electrical machine, by factoring
in the torque which reduces vibrations of the vehicle, and controls
the second rotating electrical machine such that the second
rotating electrical machine outputs the torque calculated by
factoring in the torque which reduces vibrations of the vehicle to
thereby output the torque which reduces vibrations of the
vehicle.
[0010] According to this configuration, the torque to be outputted
from the second rotating electrical machine is calculated by
factoring in the torque which reduces vibrations of the vehicle.
The second rotating electrical machine is controlled to output the
torque calculated by factoring in the torque which reduces
vibrations of the vehicle to thereby output the torque which
reduces vibrations of the vehicle. It is thereby possible to
quickly reduce vibrations of the vehicle by using the rotating
electrical machine, which is superior to the engine in
responsiveness.
[0011] Further preferably, the vehicle is mounted with a power
storage mechanism for storing electric power to be supplied to the
second rotating electrical machine. The operation unit calculates a
limit value of a charging electric power value of the power storage
mechanism, calculates a limit value of a discharging electric power
value of the power storage mechanism, changes a gain in accordance
with any one of the limit value of the charging electric power
value and the limit value of the discharging electric power value,
calculates torque requested by a driver, and calculates the torque
which reduces vibrations of the vehicle, by using a product of the
torque requested by the driver and the gain.
[0012] According to this configuration, the power storage mechanism
stores the electric power to be supplied to the second rotating
electrical machine. The limit value of the charging electric power
value of the power storage mechanism and the limit value of the
discharging electric power value of the power storage mechanism are
calculated. In accordance with any one of the limit value of the
charging electric power value and the limit value of the
discharging electric power value, the gain is changed. Furthermore,
the torque requested by the driver is calculated. By using the
product of the torque requested by the driver and the gain, the
torque which reduces vibrations of the vehicle is calculated. It is
thereby possible to set the torque to be outputted for reducing
vibrations of the vehicle, in accordance with any one of the limit
value of the charging electric power value and the limit value of
the discharging electric power value. Therefore, it is possible to
prevent the electric power that goes beyond the capability of the
power storage mechanism from being supplied to the power storage
mechanism, and prevent the electric power that goes beyond the
capability of the power storage mechanism from being discharged
from the power storage mechanism. As a result, it is possible to
achieve both of the reduction in vibrations with use of the second
rotating electrical machine and protection of the power storage
mechanism.
[0013] Further preferably, the vehicle further includes an
atmospheric pressure sensor for detecting an atmospheric pressure.
The operation unit changes a gain in accordance with the
atmospheric pressure, calculates torque requested by a driver, and
calculates the torque which reduces vibrations of the vehicle, by
using a product of the torque requested by the driver and the
gain.
[0014] According to this configuration, the gain is changed in
accordance with the detected atmospheric pressure. Furthermore, the
torque requested by the driver is calculated. By using the product
of the torque requested by the driver and the gain, the torque
which reduces vibrations of the vehicle is calculated. It is
thereby possible to set the torque to be outputted for reducing
vibrations of the vehicle, in accordance with the atmospheric
pressure. Therefore, in the case that a surge voltage is likely to
occur because of a low atmospheric pressure, the torque to be
outputted by the second rotating electrical machine, namely, the
electric power to be supplied to the second rotating electrical
machine can be reduced. As a result, it is possible to achieve both
of the reduction in vibrations with use of the second rotating
electrical machine and protection of the second rotating electrical
machine.
[0015] Further preferably, the operation unit calculates torque to
be outputted from the engine by factoring in the torque which
reduces vibrations of the vehicle, and controls the engine such
that the engine outputs the torque calculated by factoring in the
torque which reduces vibrations of the vehicle to thereby output
the torque which reduces vibrations of the vehicle.
[0016] According to this configuration, the torque to be outputted
from the engine is calculated by factoring in the torque which
reduces vibrations of the vehicle. The engine is controlled to
output the torque calculated by factoring in the torque which
reduces vibrations of the vehicle to thereby output the torque
which reduces vibrations of the vehicle. It is thereby possible to
reliably reduce vibrations of the vehicle by using the engine,
which is less likely to be influenced by an output limit of the
battery and the like, when compared with the rotating electrical
machine.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a schematic configuration diagram showing a hybrid
vehicle mounted with a controller according to a first embodiment
of the present invention.
[0018] FIG. 2 is a diagram showing a power split device.
[0019] FIG. 3 is a (first) nomographic chart showing the relation
among revolution speeds of an engine, an MG (1), and an MG (2).
[0020] FIG. 4 is a functional block diagram of an ECU, which is the
controller according to the first embodiment of the present
invention.
[0021] FIG. 5 is a flowchart showing a control structure of a
program executed by the ECU, which is the controller according to
the first embodiment of the present invention.
[0022] FIG. 6 is a diagram showing torques achieved by the engine,
the MG (1), and the MG (2).
[0023] FIG. 7 is a functional block diagram of an ECU, which is a
controller according to a second embodiment of the present
invention.
[0024] FIG. 8 is a flowchart showing a control structure of a
program executed by the ECU, which is the controller according to
the second embodiment of the present invention.
[0025] FIG. 9 is a functional block diagram of an ECU, which is a
controller according to a third embodiment of the present
invention.
[0026] FIG. 10 is a (first) diagram showing a gain G.
[0027] FIG. 11 is a flowchart showing a control structure of a
program executed by the ECU, which is the controller according to
the third embodiment of the present invention.
[0028] FIG. 12 is a functional block diagram of an ECU, which is a
controller according to a fourth embodiment of the present
invention.
[0029] FIG. 13 is a (second) diagram showing gain G.
[0030] FIG. 14 is a flowchart showing a control structure of a
program executed by the ECU, which is the controller according to
the fourth embodiment of the present invention.
BEST MODES FOR CARRYING OUT THE INVENTION
[0031] The embodiments of the present invention will hereinafter be
described with reference to the drawings. In the following
description, the same parts are provided with the same reference
characters, and have the same names and functions. Therefore, the
detailed description thereof will not be repeated.
First Embodiment
[0032] With reference to FIG. 1, description will be made on a
hybrid vehicle having a controller according to a first embodiment
of the present invention. The vehicle includes an engine 100
serving as an internal combustion engine, an MG (Motor Generator)
(1) 200, an MG (2) 300, a power split device 400, an inverter (1)
500, an inverter (2) 600, a battery 700, and a converter 800. The
vehicle runs by driving force obtained from at least any one of
engine 100 and MG (2) 300.
[0033] Engine 100, MG (1) 200, and MG (2) 300 are connected via
power split device 400. Motive power generated by engine 100 is
divided by power split device 400 into two paths. One of the paths
is for driving wheels 900 through a reduction gear, while the other
of the paths is for driving MG (1) 200 to generate electric
power.
[0034] MG (1) 200 is a three-phase alternating-current motor. MG
(1) 200 generates electric power by the motive power generated by
engine 100 and divided by power split device 400. The electric
power generated by MG (1) 200 is used in various manners depending
on a running state of the vehicle and an SOC (State Of Charge) of
battery 700. For example, during normal running, the electric power
generated by MG (1) 200 is simply used as electric power for
driving MG (2) 300. In contrast, if the SOC of battery 700 is below
a predetermined value, the electric power generated by MG (1) 200
is converted by inverter 500 from an alternating current to a
direct current, and then stored in battery 700 with its voltage
regulated by converter 800.
[0035] When MG (1) 200 acts as an electric power generator, MG (1)
200 produces negative torque. Here, the negative torque represents
torque that serves as a load of engine 100. When MG (1) 200
receives electric power to act as a motor, MG (1) 200 produces
positive torque. Here, the positive torque represents torque that
does not serve as a load of engine 100, namely, torque that assists
engine 100 to rotate. The same applies to MG (2) 300.
[0036] MG (2) 300 is a three-phase alternating-current motor. MG
(2) 300 is driven by at least any of the electric power stored in
battery 700 and the electric power generated by MG (1) 200.
Electric power converted by inverter (2) 600 from a direct current
to an alternating current is supplied to MG (2) 300.
[0037] Driving force of MG (2) 300 is transmitted to the wheels
through the reduction gear. MG (2) 300 thereby assists engine 100,
and allows the vehicle to run by the driving force supplied from MG
(2) 300 itself.
[0038] In contrast, when the hybrid vehicle is under regenerative
braking, MG (2) 300 is driven by wheels 900 through the reduction
gear to act as an electric power generator. MG (2) 300 thereby acts
as a regenerative brake that converts braking energy into electric
power. The electric power generated by MG (2) 300 is stored in
battery 700 through inverter (2) 600.
[0039] Battery 700 is a battery pack configured by integrating a
plurality of battery cells into a battery module, and furthermore,
connecting a plurality of the battery modules in series. A
discharging voltage from battery 700 and a charging voltage to
battery 700 are regulated by converter 800. A capacitor may be
provided instead of, or in addition to, battery 700.
[0040] The electric power stored in battery 700 is also supplied to
auxiliary machines, in addition to MG (1) 200 and MG (2) 300.
Charging of battery 700 and discharging of battery 700 are
controlled to achieve an SOC of, for example, 60%.
[0041] Engine 100, inverter (1) 500, inverter (2) 600, and
converter 800 are controlled by an ECU (Electronic Control Unit)
1000. ECU 1000 includes an HV (Hybrid Vehicle)_ECU 100, an MG_ECU
1020, and an engine ECU 1030.
[0042] The controller according to the present embodiment is
implemented by ECU 1000 executing a program recorded in, for
example, a ROM 1002. The program to be executed by ECU 1000 may be
recorded in a recording medium such as a CD (Compact Disc) or a DVD
(Digital Versatile Disc), and distributed on the market.
[0043] A signal indicative of a vehicle speed is inputted from a
vehicle speed sensor 2000, a signal indicative of a position of an
accelerator pedal (not shown) is inputted from an accelerator pedal
position sensor 2002, a signal indicative of force on a brake pedal
(not shown) is inputted from a brake pedal force sensor 2004, a
signal indicative of a shift position (a position of a shift lever)
is inputted from a position switch 2006, and a signal indicative of
a revolution speed of wheels 900 is inputted from a wheel speed
sensor 2008, to HV_ECU 1010.
[0044] Further, a signal indicative of a temperature of battery 700
is inputted from a temperature sensor 2010, a signal indicative of
a voltage of battery 700 is inputted from a voltage sensor 2012, a
signal indicative of a current of battery 700 is inputted from a
current sensor 2014, and a signal indicative of an atmospheric
pressure is inputted from an atmospheric pressure sensor 2016, to
HV_ECU 1010.
[0045] HV_ECU 1010 calculates a charging electric power value and a
discharging electric power value of battery 700 based on the
vehicle speed, the accelerator pedal position, the brake pedal
force, the shift position, and others. HV_ECU 1010 also calculates
an charging electric power limit value WIN (maximum value of
charging electric power) and a discharging electric power limit
value WOUT (maximum value of discharging electric power) of battery
700 based on, for example, the temperature, the SOC, and the like
of battery 700. The charging electric power value and the
discharging electric power value of battery 700 are calculated such
that they do not go beyond the respective limit values thereof.
[0046] HV_ECU 1010, MG_ECU 1020, and engine ECU 1030 are connected
such that they can send and receive signals to and from one
another. HV_ECU 1010 calculates, for example, driving forces to be
achieved by engine 100, MG (1) 200, and MG (2) 300, based on a
signal inputted to each of the ECUs and a program and a map stored
in a memory (not shown).
[0047] MG_ECU 1020 controls inverter (1) 500 and inverter (2) 600
based on the driving force to be achieved by MG (1) 200 and the
driving force to be achieved by MG (2) 300, and thereby controls MG
(1) 200 and MG (2) 300. Engine ECU 1030 controls engine 100 based
on the driving force to be achieved by engine 100.
[0048] With reference to FIG. 2, power split device 400 will
further be described. Power split device 400 is configured with a
planetary gear including a sun gear 402, a pinion gear 404, a
carrier 406, and a ring gear 408. In other words, power split
device 400 is a differential.
[0049] Pinion gear 404 engages with sun gear 402 and ring gear 408.
Carrier 406 rotatably supports pinion gear 404. Sun gear 402 is
coupled to a rotary shaft of MG (1) 200. Carrier 406 is coupled to
a crankshaft of engine 100. Ring gear 408 is coupled to a rotary
shaft of MG (2) 300 and to reduction gear 1100. Accordingly, torque
is eventually transmitted from ring gear 408 to wheels 900.
[0050] Engine 100, MG (1) 200, and MG (2) 300 are coupled through
power split device 400 formed of a planetary gear, and hence the
revolution speeds of engine 100, MG (1) 200, and MG (2) 300 have a
relation in which they are linearly connected with one another in a
nomographic chart as shown in FIG. 3.
[0051] With reference to FIG. 4, description will be made on
functions of ECU 1000 serving as the controller according to the
present embodiment. The functions described below may be
implemented by hardware or may be implemented by software.
[0052] ECU 1000 includes a first requested driving force
calculation unit 3000, a requested driving power conversion unit
3100, a charge/discharge request unit 3102, a running power
calculation unit 3104, a first driving force calculation unit 3106,
an engine control unit 3108, an MG (1) control unit 3110, a brake
force calculation unit 3200, a feedforward torque calculation unit
3202, a second requested driving force calculation unit 3204, a
feedback torque calculation unit 3206, a second driving force
calculation unit 3208, and an MG (2) control unit 3210.
[0053] First requested driving force calculation unit 3000
calculates first requested driving force, which is torque requested
by a driver, in accordance with a map including a vehicle speed, an
accelerator pedal position, and a shift position as parameters. The
map used for calculating the first requested driving force is
created in advance by simulations, experiments, or the like, and
recorded in ROM 1002.
[0054] In the present embodiment, driving force is expressed in the
unit "N (newton)", and torque is expressed in the unit "Nm (newton
meter)". Torque is calculated by multiplying driving force by a
radius of wheels 900. For the radius of wheels 900, a constant is
used. Accordingly, it is possible to calculate torque by
calculating driving force. Conversely, it is possible to calculate
driving force by calculating torque.
[0055] Requested driving power conversion unit 3100 converts the
first requested driving force into requested driving power by
multiplying the first requested driving force by a revolution speed
of wheels 900, a radius of wheels 900, and the like. In the present
embodiment, power is expressed in the unit "kW (kilowatt)". It is
noted that a technique well known in the field of hybrid vehicles
may be utilized for a method of converting driving force into
power, and hence the detailed description thereof will not be
repeated here.
[0056] Charge/discharge request unit 3102 calculates a charging
electric power value of battery 700 and a discharging electric
power value of battery 700, requested for a purpose other than
running of the vehicle, in the case that the SOC of battery 700 is
decreased, the case that electric power is to be supplied to
auxiliary machines, or other cases. In the present embodiment, a
charging electric power value and a discharging electric power
value are expressed in the unit "kW".
[0057] Running power calculation unit 3104 calculates output powers
of engine 100, MG (1) 200, and MG (2), respectively (in the unit
"kW"). Each output power is set such that the optimal fuel economy
is obtained, and that a total value of these output powers is equal
to a value obtained by adding the charging electric power value of
battery 700 or the discharging electric power value of battery 700
to the requested driving power.
[0058] First driving force calculation unit 3106 calculates driving
force to be achieved by engine 100 and MG (1) 200. The driving
force to be achieved by engine 100 and MG (1) 200 is calculated by
output powers of engine 100 and MG (1) 200, respectively.
[0059] Engine control unit 3108 controls engine 100 such that the
driving force calculated by first driving force calculation unit
3106 is achieved. MG (1) control unit 3110 controls MG (1) 200 such
that the driving force calculated by first driving force
calculation unit 3106 is achieved.
[0060] Brake force calculation unit 3200 calculates brake force (in
the unit "N") requested for braking the vehicle, based on the force
on a brake pedal, detected by brake pedal force sensor 2004. For
example, with larger pedal force, larger brake force is
calculated.
[0061] Feedforward torque calculation unit 3202 calculates a
feedforward term of the torque which reduces vibrations of the
vehicle, by inputting a sum of the first requested driving force
and the brake force into a vehicle model (sprung part model).
[0062] The vehicle model refers to a model for analyzing bounce,
pitching, and the like of the vehicle, caused by torque transmitted
from wheels 900 to a road surface, an input from an outside of the
vehicle, or the like, by utilizing an equation of motion and an
equation of state of the vehicle.
[0063] Feedforward torque calculation unit 3202 uses the vehicle
model, to thereby calculate torque to be added to or subtracted
from wheels 900 so as to reduce the bounce and pitching of the
vehicle to an optimal state. The optimal value of the bounce and
pitching of the vehicle is determined by a designer.
[0064] In calculating the feedforward term of the torque, there is
used a product of a gain G and a sum of the first requested driving
force and the brake force, the sum being identified as an input
value. With larger gain G, the torque having a larger absolute
value is calculated. It is noted that a general, well-known
technique may be utilized for the vehicle model and the method of
calculating the torque which reduces vibrations of the vehicle by
using the vehicle model, and thus the detailed description thereof
will not be repeated here.
[0065] Second requested driving force calculation unit 3204
calculates second requested driving force, which is torque
requested by the driver, from the revolution speed of wheels 900
detected with use of wheel speed sensor 2008. More specifically,
the second requested driving force is calculated from an equation
of motion (F=Ma) that uses acceleration a of the vehicle obtained
from a rate of change in revolution speed of wheels 900, and
vehicle weight M.
[0066] Feedback torque calculation unit 3206 calculates a feedback
term of the torque which reduces vibrations of the vehicle, by
inputting the second requested driving force into the vehicle model
(sprung part model). In calculating the feedback term of the
torque, there is used a product of gain G and the second requested
driving force identified as an input value. With larger gain G, the
torque having a larger absolute value is calculated.
[0067] Second driving force calculation unit 3208 calculates the
driving force to be achieved by MG (2) 300. The driving force to be
achieved by MG (2) 300 is calculated by subtracting the driving
force to be achieved by engine 100 and MG (1) 200 from the sum of
the first requested driving force, the brake force, and the
feedforward term and the feedback term of the torque which reduces
vibrations of the vehicle. It is noted that the torque which
reduces vibrations of the vehicle is converted into driving force
and used.
[0068] MG (2) control unit 3210 controls MG (2) 300 such that the
driving, force calculated by second driving force calculation unit
3208 is achieved.
[0069] With reference to FIG. 5, description will be made on a
control structure of the program executed by ECU 1000 serving as
the controller according to the present embodiment. The program
described below is repeatedly executed in predetermined cycles.
[0070] In step (hereinafter the step is abbreviated as S) 100, ECU
1000 calculates the first requested driving force, which is torque
requested by the driver, in accordance with the map including a
vehicle speed, an accelerator pedal position, and a shift position
as parameters.
[0071] In S102, ECU 1000 converts the first requested driving force
into requested driving power, by multiplying the first requested
driving force by the revolution speed, the radius, and the like of
wheels 900.
[0072] In S104, ECU 1000 calculates the charging electric power
value of battery 700 and the discharging electric power value of
battery 700, which are requested for a purpose other than running
of the vehicle.
[0073] In S106, ECU 1000 calculates output powers of engine 100, MG
(1) 200, and MG (2), respectively.
[0074] In S108, ECU 1000 calculates the driving force to be
achieved by engine 100 and MG (1) 200.
[0075] In S110, ECU 1000 calculates the brake force requested for
braking the vehicle, based on the force on a brake pedal detected
by brake pedal force sensor 2004.
[0076] In S112, ECU 1000 calculates the feedforward term of the
torque which reduces vibrations of the vehicle, by inputting the
sum of the first requested driving force and the brake force into
the vehicle model.
[0077] In S114, ECU 1006 calculates the second requested driving
force, which is torque requested by the driver, from the revolution
speed of wheels 900 detected with use of wheel speed sensor
2008.
[0078] In S116, EUC 1000 calculates the feedback term of the torque
which reduces vibrations of the vehicle, by inputting the second
requested driving force into the vehicle model.
[0079] In S118, ECU 1000 calculates the driving force to be
achieved by MG (2) 300, by subtracting the driving force to be
achieved by engine 100 and MG (1) 200 from the sum of the first
requested driving force, the brake force, and the feedforward term
and the feedback term of the torque which reduces vibrations of the
vehicle.
[0080] In S120, ECU 1000 controls engine 100, MG (1) 200, and MG
(2) 300 such that each of the driving forces is achieved.
[0081] Description will be made on an operation of ECU 1000 serving
as the controller according to the present embodiment, based on the
above-described structure and flowchart.
[0082] During running of the vehicle, the first requested driving
force, which is torque requested by the driver, is calculated in
accordance with the map including a vehicle speed, an accelerator
pedal position, and a shift position as parameters (S100). By
multiplying the first requested driving force by the revolution
speed of wheels 900, the radius of wheels 900, and the like, the
first requested driving force is converted into requested driving
power (S102).
[0083] Further, the charging electric power value of battery 700
and the discharging electric power value of battery 700, both of
which are requested for a purpose other than running of the
vehicle, are calculated (S104). From the requested driving power,
the charging electric power value of battery 700, and the
discharging electric power value of battery 700, output power of
each of engine 100, MG (1) 200, and MG (2) is calculated
(S106).
[0084] From the output powers of engine 100 and MG (1) 200,
respectively, the driving force to be achieved by engine 100 and MG
(1) 200 is calculated (S108).
[0085] In addition, based on the force on a brake pedal detected by
brake pedal force sensor 2004, the brake force requested for
braking the vehicle is calculated (S110). By inputting the sum of
the first requested driving force and the brake force into the
vehicle model, the feedforward term of the torque which reduces
vibrations of the vehicle is calculated (S112).
[0086] Further, from the revolution speed of wheels 900 detected
with use of wheel speed sensor 2008, the second requested driving
force, which is torque requested by the driver, is calculated
(S114). By inputting the second requested driving force into the
vehicle model, the feedback term of the torque which reduces
vibrations of the vehicle is calculated (S116).
[0087] By subtracting the driving force to be achieved by engine
100 and MG (1) 200 from the sum of the first requested driving
force, the brake force, and the feedforward term and the feedback
term of the torque which reduces vibrations of the vehicle, the
driving force to be achieved by MG (2) 300 is calculated (S118). In
other words, by factoring in the torque which reduces vibrations of
the vehicle, the driving force to be achieved by MG (2) 300 is
calculated. It is thereby possible to allow the torque which
reduces vibrations of the vehicle to be incorporated into the
driving force, namely, the torque achieved by MG (2) 300.
[0088] To achieve each of the calculated driving forces, engine
100, MG (1) 200, and MG (2) 300 are controlled (S120). As shown in
FIG. 6, it is thereby possible to compensate for a shortage
identified as a difference between the torque achieved by engine
100 and MG (1) 200 and the torque requested by the entire vehicle,
by means of MG (2) 300. Further, it is also possible to allow MG
(2) 300 to output the torque which reduces vibrations of the
vehicle. Therefore, it is possible to quickly reduce the vibrations
of the vehicle by MG (2) 300, which is superior to engine 100 in
its responsiveness.
[0089] As described above, with the ECU serving as the controller
according to the present embodiment in the hybrid vehicle including
a power split device having a sun gear coupled to the MG (1), a
ring gear coupled to the MG (2), and a carrier coupled to the
engine, and wheels to which torque is transmitted from the ring
gear, the MG (2) is controlled to output the torque which reduces
vibrations of the vehicle. It is thereby possible to quickly reduce
vibrations with use of MG (2), which is superior to the engine
identified as an internal combustion engine in its
responsiveness.
Second Embodiment
[0090] A second embodiment of the present invention will
hereinafter be described. The present embodiment differs from the
above-described first embodiment in that engine 100 is controlled
to output the torque which reduces vibrations of the vehicle. Other
structures are the same as, and have the same functions as, those
of the first embodiment described above. Therefore, the description
thereof will not be repeated here.
[0091] With reference to FIG. 7, description will be made on
functions of ECU 1000 serving as a controller according to the
present embodiment. It is noted that the functions described below
may be implemented by hardware or may be implemented by software.
The same functions as those of the first embodiment described above
are provided with the same numbers. Therefore, the detailed
description thereof will not be repeated here.
[0092] As shown in FIG. 7, output values of a feedforward torque
calculation unit 3300 and feedback torque calculation unit 3206 are
inputted into a requested driving power conversion unit 3302.
[0093] Feedforward torque calculation unit 3300 calculates a
feedforward term of the torque which reduces vibrations of the
vehicle, by inputting the first requested driving force into the
vehicle model. In calculating the feedforward term of the torque,
there is used a product of gain G and the first requested driving
force identified as an input value.
[0094] Requested driving power conversion unit 3302 converts the
sum of the first requested driving force and the feedforward term
and the feedback term of the torque which reduces vibrations of the
vehicle into requested driving power. By multiplying the first
requested driving force by the revolution speed of wheels 900, the
radius of wheels 900, and the like, and by multiplying the
feedforward term and the feedback term of the torque which reduces
vibrations of the vehicle by the revolution speed of wheels 900,
and the like, the requested driving power is calculated.
[0095] A second driving force calculation unit 3408 calculates the
driving force to be achieved by MG (2) 300, by subtracting the
driving force to be achieved by engine 100 and MG (1) 200 from the
sum of the first requested driving force and the brake force.
[0096] With reference to FIG. 8, description will be made on a
control structure of a program executed by ECU 1000 serving as the
controller according to the present embodiment. The program
described below is repeatedly executed in predetermined cycles. It
is noted that the same processing as that of the first embodiment
described above is provided with the same step number. Therefore,
the detailed description thereof will not be repeated here.
[0097] In S200, ECU 1000 calculates the feedforward term of the
torque which reduces vibrations of the vehicle, by inputting the
first requested driving force into the vehicle model.
[0098] In S202, ECU 1000 calculates the second requested driving
force, which is torque requested by the driver, from the revolution
speed of wheels 900 detected with use of wheel speed sensor
2008.
[0099] In S204, EUC 1000 calculates the feedback term of the torque
which reduces vibrations of the vehicle, by inputting the second
requested driving force into the vehicle model.
[0100] In S206, ECU 1000 converts the sum of the first requested
driving force and feedforward term and the feedback term of the
torque which reduces vibrations of the vehicle into requested
driving power.
[0101] In S208, ECU 1000 calculates the driving force to be
achieved by MG (2) 300, by subtracting the driving force to be
achieved by engine 100 and MG (1) 200 from the sum of the first
requested driving force and the brake force.
[0102] By doing so, it is possible to allow the torque which
reduces vibrations of the vehicle to be incorporated into the
driving force, namely, the torque achieved by engine 100.
Therefore, it is possible to reliably reduce vibrations of the
vehicle by using the engine, which is less likely to be influenced
by an output limit of battery 700 and the like.
Third Embodiment
[0103] A third embodiment of the present invention will hereinafter
be described. The present embodiment differs from the
above-described first embodiment in that gain G, which is used in
calculating the torque which reduces vibrations of the vehicle, is
changed in accordance with a charging electric power limit value
WIN or a discharging electric power limit value WOUT of battery
700. Other structures are the same as those of the first embodiment
described above. Therefore, the detailed description thereof will
not be repeated here.
[0104] With reference to FIG. 9, description will be made on
functions of ECU 1000 serving as a controller according to the
present embodiment. It is noted that the functions described below
may be implemented by hardware or may be implemented by software.
Further, the same functions as those of the first embodiment
described above are provided with the same numbers. Therefore, the
detailed description thereof will not be repeated here.
[0105] A limit value calculation unit 3500 shown in FIG. 9
calculates charging electric power limit value WIN of battery 700
and discharging electric power limit value WOUT of battery 700,
based on a temperature, an SOC, and others of battery 700. For
example, in accordance with a map including a temperature and an
SOC of battery 700 as parameters, charging electric power limit
value WIN and discharging electric power limit value WOUT are
calculated.
[0106] A change unit 3502 changes gain G used in calculating the
torque which reduces vibrations of the vehicle, namely, gain G used
in feedforward torque calculation unit 3202 and feedback torque
calculation unit 3206, in accordance with charging electric power
limit value WIN and discharging electric power limit value
WOUT.
[0107] As shown in FIG. 10, gain G is changed such that it becomes
smaller as charging electric power limit value WIN or discharging
electric power limit value WOUT is smaller. It is noted that the
method of changing the gain is not limited thereto. The gain may be
changed in accordance with any one of the charging electric power
limit value WIN and discharging electric power limit value
WOUT.
[0108] With reference to FIG. 11, description will be made on a
control structure of a program executed by the ECU serving as the
controller according to the present embodiment. It is noted that
the program described below is executed in addition to the program
in the first embodiment described above.
[0109] In S300, ECU 1000 calculates charging electric power limit
value WIN of battery 700 and discharging electric power limit value
WOUT of battery 700. In S302, ECU 1000 changes gain G used in
calculating the torque which reduces vibrations of the vehicle, in
accordance with charging electric power limit value WIN and
discharging electric power limit value WOUT.
[0110] By doing so, it is possible to decrease an absolute value of
the torque calculated for suppressing vibrations of the vehicle, as
charging electric power limit value WIN or discharging electric
power limit value WOUT is smaller. It is thereby possible to
further reduce electric power to be generated and electric power to
be consumed at MG (2) 300, as charging electric power limit value
WIN or discharging electric power limit value WOUT is smaller.
Therefore, it is possible to prevent the charging electric power
value of battery 700 from going beyond charging electric power
limit value WIN, and prevent the discharging electric power value
of battery 700 from going beyond discharging electric power limit
value WOUT. Consequently, it is possible to achieve both of
reduction in vibrations with use of MG (2) 300 and protection of
battery 700.
Fourth Embodiment
[0111] A fourth embodiment according to the present invention will
hereinafter be described. The present embodiment differs from the
above-described first embodiment in that gain G used in calculating
the torque which reduces vibrations of the vehicle is changed in
accordance with an atmospheric pressure. Other structures are the
same as those of the first embodiment described above. Therefore,
the detailed description thereof will not be repeated here.
[0112] With reference to FIG. 12, description will be made on
functions of ECU 1000 serving as a controller according to the
present embodiment. It is noted that the functions described below
may be implemented by hardware or may be implemented by software.
Further, the same functions as those of the first embodiment
described above are provided with the same numbers. Therefore, the
detailed description thereof will not be repeated here.
[0113] An atmospheric pressure detection unit 3600 shown in FIG. 12
detects an atmospheric pressure based on a signal transmitted from
atmospheric pressure sensor 2016. A change unit 3602 changes gain G
used in calculating the torque which reduces vibrations of the
vehicle, namely, gain G used in feedforward torque calculation unit
3202 and feedback torque calculation unit 3206, in accordance with
the atmospheric pressure. As shown in FIG. 13, gain G is changed
such that it becomes smaller as the atmospheric pressure is lower.
It is noted that the method of changing the gain is not limited
thereto.
[0114] With reference to FIG. 14, description will be made on a
control structure of a program executed by the ECU serving as the
controller according to the present embodiment. It is noted that
the program described below is executed in addition to the program
in the first embodiment described above.
[0115] In S400, ECU 1000 detects an atmospheric pressure based on
the signal transmitted from atmospheric pressure sensor 2016. In
S402, ECU 1000 changes gain G used in calculating the torque which
reduces vibrations of the vehicle, in accordance with the
atmospheric pressure.
[0116] By doing so, as the atmospheric pressure is lower, it is
possible to further decrease an absolute value of the torque
calculated for suppressing vibrations of the vehicle. Accordingly,
it is possible to further reduce electric power to be generated and
electric power to be consumed at MG (2) 300, in the case that a
surge voltage is likely to occur because of a low atmospheric
pressure. Therefore, it is possible to prevent an excessive rise in
an operating voltage of MG (2) 300. Consequently, both of reduction
in vibrations with use of MG (2) 300 and protection of MG (2) 300
can be achieved.
[0117] It is noted that, instead of detecting an atmospheric
pressure with use of atmospheric pressure sensor 2016, an altitude
may be detected with use of a navigation system. In this case,
change may be made such that gain G becomes smaller with a higher
altitude.
[0118] It should be understood that the embodiments disclosed
herein are illustrative and not limitative in all aspects. The
scope of the present invention is shown not by the description
above but by the scope of the claims, and is intended to include
all modifications within the equivalent meaning and scope of the
claims.
* * * * *